Player-piano and pump therefor.



C. FREBORG.

PLAYER PIANO AND PUMP THEREFOR.

APPLICATION FILED FEB. 7. I914- 1,267,859. Patented May28,1918.

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My M J2 J C. FREBORG.

PLAYER PIANO AND PUMP THEREFOR.

APPLICATION FILED FEB- 7 I914. 1 ,267,859. Patenre-d May 28, 1918.

5 SHEETS-SHEET 2.

C. FREBORG.

PLAYER PIANO AND PUMP THEREFOR.

APPLNSATION FILED r:a.1. 1914.

Patented 7 May 28, 1918;

5 SHEETS-SHEIETv 3.

Czar/es ,E60i7 i 4/%W%% was C. FREBORG.

PLAYER PIANO AND PUMP THEREFOR.

APPLICATION FILED FEB. T. 1914- A 1 ,267,859. Patented May 28, 1918.

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C. FREBORG.

PLAYER PIANO AND PUMP THEREFOR.

APPLICATION F|LED FEB-7.19I4- 1 ,267,859. Patented May 28, 1918".

5 $HEETSSHEET 5- CHARLES FREBORG, OF KANKAKEE, ILLINOIS.

PLAYER-PIANO AND PUMP THEREFOR.

Specification of Letters Patent.

Patented May 28, 1918.

Application filed February 7, 1914. Serial No. 817,145.

To all whom it may concern:

Be it known that I, CHARLES FREBORG, a citizen of the United States,residing at Kankakee, in the county of Kankakee and State of Illinois,have invented certain new and useful Improvements in Player-Pianos andPumps Therefor, of which the following is a specification.

This invention relates to improvements in player pianos and pumpstherefor. It is well known that player pianos of the type known aspneumatically actuated, are subject to a number of defects, among whichis the fact that owing to the irregular opera tion of the actuatingmeans there are fluctuations in the air pressure, which is negative orbelow atmospheric in the ordinary type, and this in a number ofinstances results in variations of speed and tone of the music.

My invention aims to overcome this defect as far as possible, byproviding a new form of easily operated pump, in conjunction with what Iterm a vacuum box or storage chamher together with a new and improvedarrangement or combination of vacuum line ducts communicating with theactuating pneumatics and motor.

My invention aims to maintain this partial vacuum or negative pressurein the vacuum line substantially uniform throughout the same and alsoaims to provide means which will keepsaid reduced pressure substantially uniform during the intermittent alternate operation. of thefoot pedals.

I also provide means for mounting and arranging my improved constructionso that the same may be readily swung to position which I terminoperative position for inspection, repair or the like.

My invention further comprises an improved form of foot actuatedoperating means and in this connection I have pro vided an improvedarrangement and mounting to enable swinging of the pedals and alliedmechanism to inoperative position within the lower part of the pianowherein they will be concealed and out of the way.

I further provide, in connection with these features, an improvedmechanism to prevent entrance of mice or the like through the slots inthe toe-rail provided for the pedal mechanism.

Still another object of my invention is the construction of pumpingelements of the cylinder and piston type and their mounting and use inpianos of the type mentioned, thereby providing a more positive andeliicient air exhausting means than that commonly used such as bellowsor the like, and my whole construction enables me to make the mechanismmuch more accessible, reduces the weight thereof and simplifies theconstruction in general so that I am enabled to present and construct,in a compact form, the required structure,a great advantage in playerpianos.

These and other objects will be fully set forth and described in thefollowing specification and accompanying drawings, in which:

Figure l is a front elevation of my player piano construction;

Fig. 2 is a front elevation on an enlarged scale of a portion of thesame;

Fig. 3 is a transverse section through a portion of the,piano showing aportion of the mechanism;

Fig. 4 is a view similar to Fig. 3 showing pedals and actuating meansswung to inoperative position;

Fig. 5 is a detail partially in section of the vacuum box head;

Fig. 6 is a plan view of the same;

Fig. 7 is a detail of the closing means for a pedal tube slot;

Fig. 8 is a vertical section through the same;

Fig. 9 ]S a section taken along the line 99 of Fig. 7.

Like numerals refer to like elements throughout the drawings, .in which;

10 designates generally the lower front in terior of a piano having thebase board 11 and toe rail 12. 13 indicates generally the keyboardsupported upon the usual legs or pedestals 14;. Blocks 15 are carried bythe base board 11, as shown for example in Figs. 1, 3 and 4;. To theseblocks are secured outwardly extending pins 16 on which are fitted theslotted portions 17 of the pedestals 17, the slotted portions 17 beinglocated in the bases or feet of these pedestals, the latter beingprovided with the lugs 17 adapted to rest on the blocks 15, as shown inFig. 4. This construction will enable the pedestal 17 to be swunginwardly or outwardly. The pedestals 17 have the outwardly extendingshelf portions 17 from which extend downwardly the arms 17 see Fig. 1,and upon each of these shelf portions 17 are located a pair of cylinders18. Mounted in each of the cylinders 18 is piston 19 adapted toreciprocate therein and provided with the downwardly extending pistonrod 19 secured thereto. A spring 20 is coiled about each of the pistonrods 19 and extends from the lower side of the pistons 19 to the lowerportion of the cylinder 18, as shown for example in Fig. 2. The pistonrods 19 are of a size permitting their lower portions to extenddownwardly of the cylinders 18 and have their lower extremities attachedto the upper end of a tape or flexible member 21. The cylinders 18 areeach provided with the heads or caps 22 fitting on the upper end thereofand apertured at 22 A manifold 23 has the elbow 23 communicating withthe interior of the cylinders 18, being secured or attached to theupperportion of the heads 22, as shown in Fig. 2. A manifold 23 is providedfor each pair of these cylinders 18, as will be further described below.The manifolds 23 are flattened on their upper portion and open, asindicated by numeral 23 A flap or valve 24; normally rests on themanifold 23 to close the opening 23 being slidably mounted upon thescrews or studs25, this flap or valve 24: being preferably constructedof rubber or other -flexible material, the action being such that whenthe pistons 19 are moved upwardly in the cylinder 18, valve 24k will bemoved off the manifold to permit exhaust of air from the cylinder andwhen the pistons are reversed the valve 2 l will close the opening 23 toprevent entrance of air therein. Tapes or flexible members 21 each havean end secured upon a pulley or wheel 26, a pair of adjacent pulleysbeing secured to a common shaft 27 for rotation therewith. These tapes21 are partially coiled around the respective pulleys 26 and it isobvious that rotation of the latter in the proper direction will operateto draw the pistons 19 downwardly in the cylinder against the action ofthe springs 20, the latter serving to return the pistons to their upperposition when actuating force is removed from the pulleys 26. The shafts27 are journaled in the supporting legs of the pedestal l7 and a collar27 may be applied to said shaft to prevent its longitudinal movementwith respect to pedestal member 17. Adjacent one extremity of each shaft27 is located a pulley 23 secured thereto and prevented from movingoutwardly thereon by the collar 27. A flexible tape or member 30 has oneend secured to the pulley wheel 28 and extends partially therearound,its other end being secured to the extremity 31 of the rod 31. (See Fig.3.) This rod is reciprocably mounted in a tube 32 which carries at oneextremity an elbow 32 and a spring 32 extends from and is attached tothis elbow 32", its other end being secured to the base board or thelike of the piano frame, this spring being under tenslon when 111 theposition shown in F 1g. 3. At its other end the tube 32 carries theeasing 32 having the upwardly extending arm or arms 32 to which arepivotally attached lugs 33 of a foot pedal 33. The latter has an elbowor arm 33 extending downwardly into the casing 32 and pivotally attachedto the rod 31, the latter being loosely mounted in the tube 32. It isobvious that oscillation of the pedal downwardly will operate topartially rotate the pulley 28 in the direction of the arrow, (see Fig.3), op erating through the medium of the shaft 27, flexible members 21and piston rods 19 to draw downwardly the pistons 19 in their respectivecylinders to create a partial vacuum or reduced pressure in the saidcylinders. The springs 20 will operate when the pressure on the pedalsis removed to return the same, together with the associated mechanism,to the position shown in Fig. 3, which is normal position. The elbow 32has a pivotal connection at 32 to the base of the bracket 17, as isclearly shown in Figs. 3 and 41:. A panel 35 is provided in the lowerfront of the piano, this panel being provided at its upper portion withthe roller 35 slidably mounted upon a track 36 carried by the keyboard13 or the like. The usual spring 37 coacts with the portion of thispanel. 35 to prevent its accidental outward displacement. The track androller 3G-35 permit sliding of the panel to one side, to permit swingingof pedal 33, tube 32, and rod 31 to the position shown in Fig. l, thismovement being assisted by the spring 32, the latter serving to hold themechanism in the position shown in Fig. 1. When in this position thepanel may be closed being easily moved by its mounting upon the track36. The lower portion of the panel slides between-the beads or ribs 12on the upper portion of the toe rail 12, as shown in Fig. i, thisconnection being com iiaratively dust and dirt tight.

It will be apparent that the above described construction permitsmovement of the pedals, etc. to a concealed position so as not tointerfere with the operation of the piano without the player.

hat I term a vacuim'i box 40 is secured to the inner side of the sideframe member 4.1, see Fig. 1, there being one of these vacuum boxes oneach side of the piano. Each vacuum box 10 is mounted upon a bracket 12and secured thereby to the frame member ll. A piston 13 is slidablymounted in the vacuum box 4:0 and is provided with the piston rod i lextending downwardly therefrom and having one end attached to the spring45 which in turn has its other end secured to the base board or bottom11 of the piano, the spring 415 being arranged to resist upward movementof the piston 43, and also normally to return to its lowered position.The cylinder 40 is provided with the head 46 detachably secured to itsupper portion, this head being internally chambered, as indicated bynumeral 46 and having its lower wall 46 apertured, as indicated bynumeral 46, the wall 46 comprising, in effect, a partition between thechambers 46 and the interior of the vacuum box 40, the apertures 46extending between. A central boss 46 is provided in the head 46 and iscentrally apertured to permit the insertion of a duct 47 to communicatewith the interior of the box 40. A second duct 48 extends through theaper ture 46 in the head 46, the same extending from the chamber 46outwardly of the head 46. The duct 48 extends to and communicates withthe manifold 23, as shown in Fig. 2. A fiap or valve 49 rests on theupper side of partition 46 and is fitted loosely around the boss 46 thisflap 49 being of slightly less diameter than the diameter of the outerwall. of chamber 46, as shown for example in 5 and 6. The flap 49 beingformed of rubber or other flexible material and nor mally resting uponthe studs or flanges 46 or the partition 46, will operate to preventflow of air from the duct 48 into cylinder or box 40, althoughpermitting flow from the latter to the former. The duct 47 extendsupwardly in the piano and is in communication with a cross duct 50, thislatter extending across between and communicating with the two ducts 47,as shown clearly in Fig. 1.

A motor 51 provided with the intake duct 52, is supported, as show-n bythe duct- 50, and communicates through the said duct 52 therewith. Aplurality of tubes 53 also extend across between the ducts 47 and are incommunication therewith, these tubes 53 being apertured to communicatewith, and arranged to adjustably support actuating pneumatics 54.

It will be apparent, in the operation of my device, that when the pedals33 are intermittently and alternately depressed and released, themechanism described herein, will operate to intermittently andalternately depress each pair of adjacent pistons 19 in the cvlindersl8. \Vhen the pair of pistons shown in Fig. '2, for example, isdepressed against the action of the springs 20, the air will beexhausted through apertures 46 from the vacuum box 40 and from the duct47, the latter serving to transmit the resultant partial vacuum orsection to the entire vacuum line, as I term it, comprising ducts 47,cross duct 50 and cross tubes or ducts 53. At the same time thisexhausting of the air from vacuum box 40 is considerably greater thanthe amount of air ordinarily ,drawn in through the duct 47, thisdifference depending, of course, on the speed of playing the piano, thesheet of music being played, and other similar conditions. Owing to thisexcess of negative pressure obtaining in the box 40, the piston 43 willbe drawn upwardly therein against the action of the spring 45, thetension of which will be increased. The size of the vacuum box 40 havingbeen properly determined, in relation to the capacity of the pumpingmembers 18 and the negative pressure which it is necessary to create inthe line, there is no danger that piston 43 will be drawn to itsuppermost position in the ordinary opera tion of the piano. When thecorresponding foot pedal has been depressed to its lowest limit andreleased, the springs 20 will operate to return the same, as explainedabove, to normal position at the same time raising the pistons 19 in thecylinders 18 to the position shown, this upper limit being de terminedby the size of the springs 20 and nuts or collars 20" secured to thepiston rods 19 exteriorly of the cylinders 18. The air drawn into thecylinders 18 on the previous stroke is expelled through the opening 23in manifold 23 on the lip-stroke, valve 24 being raised off its seat topermit such exhausting. The valve 49 will prevent flow of air on thisup-strokc, back into the vacuum box 40, as was explained above. \Vhilethe pistons are making their rip-strokes on this side of the piano, thepressure in the vacuum line would be wholly dependent on that producedby the other pair of pumps 18, or their equivalent, and the resultingoperation would be pulsating and intermittent were it not for the piston43 in the vacuum box 40, this piston 43, as will be apparent, acting asan accumulator or the like to store up the partial pressure or vacuumproduced in the box 40 by the previous down-stroke of the pistons 19,since, at the completion of this down-stroke, the vacuum or negativepressure in the line will be maintained by the movement of the piston 43dowmvardly in the box 40 through the medium of spring 45. Inasmuch asboth pairs of pumps and both vacuum boxes 40 operate in the same manner,except that ordinarily they are alternately actuated, it is notnecessary to describe in detail the operation of both sets. It is to benoted, however, that in the event, for example, a greaterpumping effortis produced bv one side, the cross communica tion through duct 50 andtubes 53 between ducts 47 and vacuum boxes 40, will result in themaintenance of a comparatively uni form or balanced pressure in theline, as will be apparent, so that it will be apparent that I haveprovided means for producing substantiallv constant negative pressure inthe line and also means for balancing the pressure to enhance themaintenance of the uni form vacuum. WVhen the pedals and tubes 32 are inthe operative position shown in Fig. 3, the extremities of the tubes 32rest in slots 12 in the toe rail 12, see Fig. 8. Were these slotsunprotected, when the pedals are swung to inoperative position, as shownin Fig. holes would be left which would permit the entrance of mice orthe like,'a disadvantage common to many pianos and players in presentuse and to prevent this I have provided the construction shown in Figs.7, 8 and 9. A follower or cap 60 is provided with the downwardlyextending front flange 60 and angularly disposed top flange 60". A studor pin 60 extends downwardly from the flange 60 and is slotted, asindicated by numeral 60 This pin or stud 60 is slidably mounted in thetube 60 carried in the toe rail 12, the lower end of the latter beingprovided with the plug 60 centrally apertured at 60 a seat being provided in the plug for the ball 60 which normally closes the opening 60this being provided to permit entrance of air to the tube '60 to preventa vacuum forming there in which would interfere with the operation ofthis device.

A spring 60 is located in the tube 60 and extends between the lowerportion of the pin 60 and plug b0 operating normally to maintain thefollower 60 in the position shown in Figs. 7 and 9 wherein it closes theslot 19;. lVhen the pedals are moved to their operative position, asshown in Fig. 3, the tubes 81 will operate to depress follower 60, asshown in Fig. 8.

As mentioned above, the hinged or pivotal mounting of the pumps andsupporting structure will permit outward swinging of the pump apparatus,when so desired, the duct 48 being detachable to permit such movement.Inasmuch as this movement is not necessary except in case of somebreakdown or the like, I desire to rigidly support the pump mechanism inoperative position, and to accomplish this purpose I secure the upperend of bracket arm 17 by screws or the like to the block (31 carried bythe keyboard or the like of the piano, see Fig. 2.

It is believed that the above description is sulficient to enable thoseskilled in the art to understand the construction and operati 011 of mydevice without further amplification. It is obvious that the structureset forth in the specification and shown in the drawings is susceptibleof many modifications and improvements, and I do not wish to berestricted to the description or showing beyond the scope of theappended claims.

I claim 1. In combination, a pair of foot actuated air exhausting means,a vacuum box communicating with each of said means, duct memberscommunicating with each of said boxes, tubes across between and incommunication with. said first named ducts, ac-

tuating pneumatics secured to and in communication with said last namedtubes, an-

plurality of cylinders, pistons reciprocably mounted in said cylindersand having piston rods secured thereto and extending outside of saidcylinders, means to move said pistons independently of each other in onedirection, and means to independently re turn either of said pistonsafter such movement.

4C. In a device of the class described, a pump comprising a cylinder,:1. piston reciprocably mounted in said cylinder, a piston rod securedto said piston and extend ing through the end of said cylinder, means tomove said piston in one direction in said cylinder, and means to returnsaid piston after such movement, said last named means comprising aspring.

5. In a device of the class described, a pump member comprising acylinder, a piston reciprocably mounted in said cylinder, a rotatablepulley or the like, a flexible member connecting said piston to saidpulley, and means to rotate the latter to actuate said pump.

6. In a device of the class described, a pump comprising a cylinder, apiston reciprocably mounted in said cylinder, at piston rod securedthereto, a pulley member, means to rotate said pulley, and a flexibletape secured to said pulley and to said piston rod whereby rotation ofsaid pulley in the proper direction will operate to move said piston.

7. In a device of the class described, a pump comprising a cylinder, apiston reciprocably mounted in said cylinder, a piston rod securedthereto, a pulley member, means to rotate said pulley, a flexible tapesecured to said pulley and to said piston rod whereby rotation of saidpulley in the proper direction will operate to move said piston, andmeans to return said piston in the opposite direction after suchmovement.

8. In a device of the class described a pump comprising a cylinder, apiston reciprocably mounted in said cylinder, a piston rod securedthereto, a pulley member, means to rotate said pulley, a flexible tapesecured to said pulley and to said piston rod whereby rotation of saidpulley in the proper direction will operate to move said piston, andmeans to return said piston in the opposite direction after suchmovement, said means comprising a spring.

9. In a device of the class described, a pump comprising a cylinder, apiston re ciprocably mounted therein, a rotatable pulley, a flexiblemember connecting said piston to said pulley, means to rotate saidpulley, said means comprising a foot actuated member, a second pulley,and a flexible member operatively connecting said foot member to saidsecond pulley.

10. In a device of the class described, a pump comprising a cylinder, apiston reciprocably mounted therein, a rotatable pulley, a flexiblemember connecting said piston to said pulley, means to rotate saidpulley, said means comprising a foot actuated member, a second pulley,and a flexible member operatively connecting said foot member to saidsecond pulley, both said pulleys being mounted upon a shaft wherebyrotation of said last named pulley will operate to rotate saidfirst-named pulley, and vice versa.

11. In a device of the class described, an air exhausting means,actuating means to operate said air exhausting means, said actu atingmeans comprising a foot actuated member, a rotatable shaft, and aflexible member operatively connecting said foot actuated member to saidshaft.

12. In a device of the class described, an air exhausting means, meansto actuate the same, means to actuate said last named means comprising afoot pedal, a rotatable shaft, a connecting rod pivotally connected tosaid pedal, and a flexible member operatively connecting said connectingrod and said shaft.

13. In a device of the class described, a rotatable shaft, a pulleymounted upon said shaft, a flexible member having one end secured tosaid pulley adapted to Wind upon the same, a rod, a pedal, said rodbeing pivotally connected to said pedal and to said flexible member.

1 1-. In a device of the class described, a rotatable shaft, a pulleymounted upon said shaft, a flexible member having one end secured tosaid pulley adapted to wind upon the same, a rod, a pedal, said rodbeing pi votally connected to said pedal and to said flexible member,and a tube, said rod being reciprocably mounted in said tube.

15. In a device of the class described, a rotatable shaft, a pulleymounted upon said shaft, a flexible member having one end secured tosaid pulley adapted to wind upon the same, a rod, a pedal, said rodbelng prvotally connected to said pedal and to said flexible member, atube, said rod being reciprocably mounted in said tube, and a supportingweb or bracket secured to said tube,

said pedal being pivotally mounted on said bracket.

16. In a device of the class described, pumping means, means to actuatesaid pumping means comprising a reciprocating rod, a tube, said rodbeing reciprocably mounted in said tube, a pedal operatively connectedto said rod, means to pivotally support said pedal, said means beingsecured to said tube, means carried by said tube adjacent one endthereof, said means being pivotally mounted, whereby said pedal, tubeand rod may be moved to operative or inoperative position.

17. In a device of the class described, pumping means, means to actuatesaid pumping means comprising a reciprocating rod, a tube, said rodbeing reciprocably mounted in said tube, a pedal operatively connected.to said rod, means to pivotally support said pedal, said means beingsocured to said tube, means carried by said tube adjacent one endthereof, said means being pivotally mounted, whereby said pedal, tubeand rod may be moved to operative from inoperative position, and viceversa, and a spring extending from said last named means to and securedto said piano, said spring being adapted to hold said pedal, tube androd in inoperative position.

18. In a device of the class described, having a toe rail, said railbeing slotted, a foot actuated means extending through said slot when inoperative position and located outwardly of said slot when ininoperative position, and means to automatically close said slot whensaid actuating means is moved therefrom to prevent entrance of mice orthe like through said slot.

19. In a device of the class described, having a toe rail, said railbeing slotted, a foot actuated means extending through said slot when inoperative position and located outwardly of said slot when ininoperative position, means to automatically close said slot when saidactuating means is moved therefrom to prevent entrance of mice or thelike through said slot, said means comprising a follower slidablymounted in said slot, and means to normally move said follower toposition closing said slot, said means comprising a rod secured to saidfollower and a spring coacting therewith.

20. In a device of the class described, having a toe rail, said railbeing slotted, a foot actuated means extending through said slot when inoperative position and located outwardly of said slot when ininoperative position, means to automatically close said slot when saidactuating means is moved therefrom to prevent entrance of mice or thelike through said slot, said means comprising a follower slidablymounted in said slot,

means to normally move said follower to position closing said slot, saidmeans comprising a rod secured to said follower, a

spring coacting therewith, said rod and spring being mounted in anaperture in said toe rail, said aperture being normally closed at oneend, and means to permit ingress of air thereinto.

21. In a device of the class described, a pumping member, a vacuum boxin communication therewith, said pumping member being arranged toexhaust the air from said vacuum box and thereby reduce the pressure inthe same, and means coacting with said box to maintain said reducedpressure therein.

22. In a device of the class described, a pump comprising a cylinder, apiston reciprocably mounted therein, means to reciprocate said piston insaid cylinder, a vacuum box, a duct connecting said pump and said vacuumbox, and means to permit withdrawal of said air from said box .by saidpump and to prevent passage of air from said pump to said vacuum box.

23. In combination, a pumping member comprising a plurality ofcylinders, pistons reciprocably mounted in said cylinders, a manifoldconnecting said cylinders, and means to permit outflow of air from saidcylinders when said pistons are actuated in one direction, said meansbeing adapted to prevent entrance of air therethrough when said pistonsare moved in the opposite direction.

2%. In combination with a piano or the like, a pumping member located inthe lower portion thereof, a frame, said pump being carried by saidframe, said frame being hingedly mounted to move bodily outward withsaid pumping member when so desired.

In combination with a piano or the like, a pumping member located in thelower portion thereof, a frame, said pump being carried by said frame,said frame being provided with pedestal portions pivotally attached tothe frame of said piano whereby said frame and pumping member may behingcdly swung outwardly of said piano.

26. In combination with a piano or the like, a pumping member located inthe lower portion thereof, a frame, said pump being carried by saidframe, said frame being provided with pedestal portions pivotallyattached to the frame of said piano whereby said frame and pumpingmember may be hingedly swung outwardly of said piano, said frame beingprovided with an arm adapted to be secured to said piano frame when inoperative position.

27. In a device of the class described, an air exhausting means, avacuum box, a duct connecting said air exhausting means with said vacuumbox, a partition in said box separating the main portion of the latterfrom said duct, said partition being apertured, and a valve normallyresting on said partition and adapted to close said aperture.

28. In combination, an air pump, a vacuum box, a duct connecting saidvacuum box with said air pump, said vacuum box being provided with apartition therein, said partition being apertured, and means to closesaid aperture to prevent flow of air from said pump to said box, saidmeans being arranged to permit exhausting of air from said box by saidpump, and a second duct communicating with the interior of said boxthrough said partition.

29. In combination with a pumping means, a vacuum box and a vacuum line,said box being provided with a head, said head being apertured tocommunicate with said box, a duct leading from said head to said pumpingmeans whereby air may be exhausted through said apertured head from saidbox to said pumping means, means to prevent reverse flow to said box,and a second duct leading through said head and communicating with saidbox.

30. In combination with a pumping means, a vacuum box and a vacuum line,said box being provided with a head, said head being apertured tocommunicate with said box, a duct leading from said head to said pumpingmeans whereby air may be exhausted through said apertured head from saidbox to said pumping means, means to prevent reverse flow to said box, asecond duct leading through said head and communicating with said box, apiston slidably mounted in said box and arranged to be moved in onedirection when the air is xhausted from said box, and means coactingwith said piston to resist such movement and to normally return the samein a reverse direction after such movement whereby air will be drawninto said box through said second named duct.

In testimony whereof, I have subscribed my name.

CHARLES FREBORG.

Witnesses VVILLIAM N. Hnrm, fRANK O. SCHNEIDER.

topies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents Washington, D. C.

